Add map helper to RegistrationController

Fixes 3 errors including:

Registration Terms of Service agreement if accepting Terms of Service is not required allows registration as normal
     Failure/Error: super

     ActionView::Template::Error:
       undefined method `using_google_maps?' for #<#<Class:0x00007fd4949c4558>:0x00007fd499dd0ae8>
     # ./app/helpers/application_helper.rb:20:in `method_missing'
     # ./app/views/registration/steps/_details.html.haml:60:in `_app_views_registration_steps__details_html_haml___1911121144363058234_70275472163280'
     # ./app/views/registration/index.html.haml:12:in `block in _app_views_registration_index_html_haml__993897347679518865_70275545598940'
     # ./app/views/registration/index.html.haml:11:in `each'
     # ./app/views/registration/index.html.haml:11:in `_app_views_registration_index_html_haml__993897347679518865_70275545598940'
     # ./lib/open_food_network/rack_request_blocker.rb:36:in `call'
     # ------------------
     # --- Caused by: ---
     # NoMethodError:
     #   undefined method `using_google_maps?' for #<#<Class:0x00007fd4949c4558>:0x00007fd499dd0ae8>
     #   ./app/helpers/application_helper.rb:20:in `method_missing'

app/controllers/registration_controller.rb

@@ -2,9 +2,12 @@ require 'open_food_network/spree_api_key_loader'
 
 class RegistrationController < BaseController
   include OpenFoodNetwork::SpreeApiKeyLoader
+
+  layout 'registration'
+  helper 'map'
+
   before_action :load_spree_api_key, only: [:index]
   before_action :check_user, except: :authenticate
-  layout 'registration'
 
   def index
     @enterprise_attributes = { sells: 'none' }